Feb 26 (Reuters) COLOMBO- Sri Lanka is set to offer a second batch of licences to explore for oil and gas, as it looks to start production in the country and ease its dependence on imported fuel.

The government said on Tuesday that it would invite companies to bid for licences on some of the 13 blocks in the Cauvery and Mannar Basins off the nation's northwest coast.

It added that details on the number of blocks would be announced shortly and that it would launch a roadshow for the process on March 7 in Houston, Texas, before moving on to London and Singapore.

The step comes after Cairn India, the only firm to buy a licence in an earlier offering, kicked off the second part of its exploration programme early this month, following the discovery of gas and condensate in the first phase.

Since the end of a three-decade war with Tamil separatists in May 2009, the government has tried to reinvigorate oil and gas exploration.

The island nation does not currently produce oil, spending $5.04 billion on imports in 2012.

Seismic work carried out earlier by Norway's TGS Nopec Geophysical Co ASA showed some potential in the northern Cauvery Basin, which on the Indian side has producing wells, and in a basin off the island's southern coast.

Sri Lanka's government has said the seismic data shows the potential for more than 1 billion barrels of oil under the sea in a 30,000 sq km area of the Cauvery basin.